Train control



Way 11 1926.

W. K. HQWE TRAIN CONTROL Filed March 4. 1922 2 Sheets-Sheet 1.

ATTORNEY May '11 1926. 1,584,224 W. K. HOWE TRAIN CONTROL Filed March 4, 1922. 2,Sheets- Sheet 2 W ZZMMI ATTORNEY Patented May 11, 1926.

rrsa s'ras WIN'IHROP K. HOWE, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF GATES, NEW YORK, A CORPORATION OF NEW YORK.

TRAIN CONTROL.-

, Application filed March 4, 1922. Serial lilo: 541,225.

This invention relates to automatic speed control systems for railroads.

This invention contemplates the provision of automatic means for checking up the speed of a train as it is governedby the engineer in a caution blockin obedlence to 'a caution signal, and applying the brakes in the event the speed is excessive to a degree that the train can not be properly stopped before reaching the stop signal in On account of variations in the length of the blocks encountered. in practice, and the braking distance of trains in different blocks, due to grades and the like, it is considered preferable to employ a system of automatic speed control which is susceptible in a simple way of adaptation or adjustment to fit the varying requirements in the several blocks.

In accordance with this invention, it is proposed to communicate the desired control influences from the trackway to moving trains, dependent upon traiiic conditions in advance, by. inductive means acting with-,

out physical contact through an intervening air gap, such means comprising in general car-carried elements adapted to cooperate with track elements. at intervals along the track to produce a controlling influence or effect upon the car. The enforcement of restricted speed limits at different points along the track is obtained in accordance with the time-distance interval principle, the track elements being spaced apart, preferabl in' pairs, to define a definite space 111- terva and a car-carried means acting automatically to produce a brake applicat on whenever the car traverses such space interval in less than a predetermined time measured by suitable timing mechanism on the car. The invention also includes provisions for perm1tting a car to run either end forward in the normal direction of trafiic and receive the proper control, and run either end forward opposite to the normal direction of trafiic, without receiving such control; and the application of means requiring the car to he rought to a stop, after an automatic brake application has occurred on account of excessive speed, in order to release the brake and proceed.

Various other characteristic features of the invention, its advantages, and adaptability to practical operating conditions,

will be pointed out hereinafter as the description of one specific embodiment progresses.

- In the accompanying drawings, Fig. 1 is a diagrammatic View showing the trackway devices and circuits according to this invention, together with braking and speed limit curves; and i Fig. 2 illustrates in a simplified and conventional manner car devices and circuits of this invention, and also a pair oftrack elements or inductors to illustrate their cooperation with the car apparatus.

In the embodiment of the invention illustrated, the transmissionof the desired controlling influences to limit the speed at several points in a block is produced by cordance with traflic conditions. arrangements of trackway circuits suitable for the purpose of controlling these track elements may be employed, and it should be understood that the arrangement shown in Fig. 1 is only a typical illustration. Re-

ferring to Fig. 1, the track rails l of the railroad track are divided by insulated oints 2 into blocks in the usual way, one

block I and the adjacent ends of two other blocks H and J being shown. The 'parts and circuits associated with the various signals S conuentionally, Without attempting to illustrate their Well-known contro circuits and devices.

In each-block are provided pairs of track elements '1 .at the several points in the block track elements which are governed in ac- Various at. which the speed of the train is to he checked, the spacing between the elements T of each pair determining the distance a train is permitted to run in a predetermined time at this point in the block. In the specific embodiment illustrated, these track elements are shown on the right side of the track "when facing in the'normal direction of traffic, as indicated by the arrow. Each of these track elements T comprises a U- shaped core 5 terminating in enlarged pole pieces 6, the back yoke of the core 5 beiug provided with a coil 7. At each pointof location of a pair of traflic controlle d track- Way elements T. is located a repeater track or line relay 8, these relays 8 being connected in multiple to the line wires 9 and 10, which are energized when the track relay the repeater track relays 8 will likewise be energized, thus closing their front contacts 16 and 17. The circults controlled by these front contacts 16 and 17 may be traced asfollows :beginning' at the front contact '16,

wires 18, 19 and 20, coil 7 of the first track element T of each pair, wire 21 back to the front contact 16; and another circuit beginning at the front contact 17,'wires 22, 19

and 23, coil 7 of the second track element ofeach pair, wire 24back to the contact 17, thereby putting the coils 7 of the track ele ments in a circuit of low resistance when the next block in advance is-clear.

The car-carried apparatus of one specific embodiment of the present invention has been illustrated in Fig. 2, and comprises suitable devices which will first be separately described. One of these devices comprises duplicate influence receiving car elements L mounted on opposite sides of the vehicle, only one of which is used atone time, dc.- pendent upon the direction of movement of the .vehicle or locomotive on which they are mounted.- These car elements L each comprise a U-shaped core 25'ter1ninating in enlairged pole-pieces 26, a primary coil P on one of the legs of the U-shaped core, and a secondary coil Son the other leg. These car elements L are preferably mounted directly on the truckof a railway vehicle and protected from excessive jars and vibrations, and from the weather in any suitable man; ner. The specific construction for the mounting of the car elements L is not within the scope of the present invention, and therefore has not been illustrated.

Y A control relay C and a repeater relay B arej provided which are particularly designed to serve the purpose for which they are intended. Although these relays have been illustrated identically, this illustration is merely conventional and the control relay C in practice is constructed with much smaller moving parts and controls smaller contacts than the repeater relay .R, and will From this it is therefore function on a smaller change of energy. Both of theserelays 1C and B have their moving parts well balanced so that they will not be affected by jars and vibrations, and are preferably mounted in a comparatively heavy spring supported relay casing, which may be provided with a glass panel and locked or sealed in any suitable manner. I

The car apparatus includes a train control device K which has been illustrated as an e-lectro-pneumaticvalve. This train control device may control the train in any suitable manner as, for instance, by venting the brake pipe when its winding 27 is deenergized. This device K is of the normally energized type and has its normally energized circuit completed through the front contact 28 controlled by the armature of its clectro-magncd. Therefore, a momentary deenergization of the train"control device K will permanently deenergize it, because its energizing circuit will be interrupted at its front contact 28.

Another element of the car-carried apparatus embodying the present invention comprises a time element or time control device TC. This time control device TC is provided to normally close an auxiliary circuit, to open this circuit a very short period after the device has been operated, to maintain this circuit open for a predetermined time, and then again close said circuit. This time control device TC may operate on any one'of the various principles used for measuring time, and has for convenience been shown as comprising a motor M, having an armature provided with a commatator 29, brushes 30, a shunt field winding 31, and a battery 32 connected across the brushesand shunt winding so as to permanently operate the motor at a constant speed. This motor is preferably one that will main-. tam a constant speed irrespective of a' slight variation in the voltage of the battery 32, and regardless of a slight change of load that may be applied thereto. This characteristic of the motor may be obtained to a large extentbyproperdesign, and if desired, a suitable speed control regulator may be incorporated therewith to give this motor a constant speed characteristic.

The motor M through the shaft 33 drives one member 34 of a friction c'utch, the other member 35 of said friction clutch being rlgidly connected to a shaft 36. provided with a worm 37. The construction of the friction clutch is such that the pressure of the sprmg 38 causes a frictional contact between the members 34. and 35, thus allow-' armature 42 pivoted at 43.

thereto but insulated therefrom a contact arm which is connected to one terminal of a battery B. As the worm wheel is rotated in the direction of the arrow by the motor M through the intervening friction clutch, the contact arm 40 is stopped by coming in contact with the dog 41 of the time starting magnet CS. This dog 41 is'connecte-d to the As the time starting magnet CS is deenergized, the spring 44 moves the dog 41 and allows the contact arm 40 to .be rotated. An auxiliary checking device toche'ck the continuous rotation of the motor M is provided. This device comprises a collar 45 rigidly fastened to the shaft 33, a collar 46 slidably mounted on this shaft and biased from the other collar 45 by a spring 47. Two pairs of links 48 are provided to connect these collars. These links are pivotally connected together and are connected to centrifugal weights 49, whereby the rotation of the shaft 33 causes the weights 49 to compress the spring 47 and shift the collar 46 along the shaft The collar 46 has connected thereto but insulated therefrom a, contact disc 50. If the motor is rotating the 'shaft 33 at the predetermined speed, this contact disc 50 will be in a positlon'to bridge contacts 51 and 52 illustrated by arrows.

In the practical operation of trains, the locomotive is usually run pilot first, but it sometimes happens that it is necessary to run a locomotive equipment tender first, and

in order to facilitate automatic train control under these conditions an automatic reversing switch is provided. This automatic reversing switch comprises a collar 53loosely mounted on the axle 54 of the vehicle, having an upstanding arm 55 bent over to form a hook 56 provided with a-hole. In this hole is contained a rod 57, having its opposite end provided with abrake-shoe 58. The

brake-shoe 58 is held into frictional engagement with the car axle 54 by a. compression spring 59. To the collar 53 is rigidly fastened but insulated therefrom a, contactor G0. On opposite sides of the contactor 60 are provided stops 61 and 62 which limit the movement of the con'tactor in one direction or the other, dependent upon the direction of movement of the train due to the frictional engagement between the axle 54 and the brake-shoe 58. This contactor is adapted to complete one or the other of the control circuits, in a manner to connect the right-hand car element L (when facing in the direction of movement of the vehicle) to the train control apparatus. 1

0perc z-tz'mn-flissuming that the car-carried apparatus is in its normal condition, that is, is moving between control points in a block when the next block in advance is c.'ear. Under these conditions, the control relay C is energized through a circuit which may be traced as follows :-beginning at the terminal B of a battery which has its other te minal connected to a common return wire N, front contact 63 of the control relay C, wires 64 and (55, winding of the control relay C, wire 66, contactor 60, wire 67, secondary coil S of the righthand car element L when facing the pilot end of the locomotive equipment, wire 68,. through the common return wire-N.

With the control relay C in its energized position, a circuit will be completed for energizing the secondary or repeater relay R through a. circuit, which may be traced as follows:-beginning at the terminal B of a battery, front contact 69, wire 70, winding of the repeater relay R, wire 71, back to the common return wire N.

The energization of the repeater relay It closes its front contacts completing the energizing circuit for the time starting magnet US, which may be traced as follows beginning at the terminal 13 of the battery, front contact 72'of the repeater relaylt, to other front contact'73, wire 74, winding of the time starting magnet CS, wire 75,"ba-ck to the common return wire N.

Another circuit which is also energized when the repeater relay R is picked up may be traced as follows:-beginning at the terminal B of the battery, front contact 72. movable contact 76, wires 77 and 78, stick contact 28 of the train control device K,

wires 79 and 80, winding 27 of the train control device K, wire 81, contact 51, contact time 50, contact 52, wire- 82, primary coil 1 of one of the car elements L, wire 83, primary coil P of the other car element L, wire 84, back to the common return wire N.

An auxiiiary circuit for energizing the train control device K may be traced. as follows:-beginning at the terminalB of the battery, contact arm 40, stationary con tact 85, wire 86, release switch 87, wire 78.- through the train control device K and pri mary coils P, to the common return wire N, in the same manner as just traced.

The energization of the primary coils 1. produces a magneto-motive-force in the cores of the car elements L, which greatly predominates the magneto motive-force 1miduced by the secondary coil S connected in the energizing circuit of the control relay C. This is due to the fact that the current flowing through the control relay C is very small, that is, it is just suflicient to maintain it in its energized position. The magnetomctive-force produced by the primary and secondary coils, although being in the same direction, produces very little flux linking both of these coils. This is due to the large air gap between the pole pieces 26.

"With'the car-carried apparatus in its normal condition as ust described, let us assume the total flux through the primary coil P. This sudden increase and decrease of flux. through the secondary coil S induces a volt-.

age therein similar to thatof a single cycle of alternating current E. M. F. The secondary winding S is so connected with re spect to the battery that the first wave of the single cycle of E. M. F. opposes that of the battery, thereby reducing the current flowing in the control relay C to an extent to drop its armature bythe action of the spring 99. Since the control relay C is connected in a stick circuit, it will be per manently deenergized until picked up by some other means.

The deenergization of'the control relay C interrupts the energizing circuit for the re-,

peater relay R, thus causing its armature to drop by the action'ot' the spring 100 and interrupt one of the circuits for'energizing the train control device K heretofore traced.

The other of said circuits being completed through the contact arm 40 is, however, intact and therefore the train control device K will not be deenergized. The deener 'zation of the repeater relay R closes a pic '-up circuit for the control relay C, which may be traced as follows :starting at the terminal B of the battery, contact arm 40, stationary contact 85, wire 86, release switch.

87, wire 77, movable contact 76 of the repeater relay R, back contact 88, wire 89, wire 65, winding of the control relay C, wire (36, contactor 60, wire (37, secondary coil S, wire 68, and back to the common'rcturn wire N. This causes the control'relay C to be again energized, causing it to complete the previous energizing circuit heretofore traced, thereby again energizing repeater relay 1i.

This momentary deeuergization' of the re- I peater relay R interrupts the normally energized circuit of the time starting magnet CS, thereby causing the dog 41 to release the contact'arm 40, thus permitting the arm 40 tostart on its cycle of rotation. The several devices are so designed and constructed that the auxiliary energizing circuit for the train control device K, which is carried through the contact arm 40, will not be interrupted until the repeater relay R has again been energized.

Let us assume that the time consumed in running from the first to the second track element of a pair is sufficient to allow the contact arm 40 to COIIIPlCtBltS travel of one revolution, and again to be stopped by the dog 41. It now the second track element is passed over, this same cycle of operation will take place without in any way aifecting the train control device K. I

Assume now that a train in passing between the first and second track element of a pair is moving at a rate of speed so as not to allow suflicient time for the contact arm 40 to reach the stationary contact 85. As the control relay C and repeater relay R, respectively, are deenergized by the passage of the car element L over the second track element T, in the same manner as heretofore described, the deenergization of the repeater relay R interrupts the circuit through the train control. device, because the auxiliary circuit is also open at the same time, since cont-act arm 40 has not yet reached stationary contact 85. Since the train control device K is connected in a stick circuit, a

momentary deenergization of the train control device K will permanently deenergize' it. The pick-up circuit or the control relay C will not be closed due to the making of the back contact 88, because there is no source of energy on the movable contact 76. As s oon as the contact arm 40 reaches the stationary contact 85, the pick-up circuit for the control relay C heretofore traced will be completed, thus causing it to pick up and again energize the repeater relay R. The energization of the repeater relay R closes the circuit for the time starting magnet CS to again move the dog 41 against the stop 90 before the contact arm 40 entirely completes its cycle. I

The train control device K having been deenergized, as just explained, causes the train to come to-a stop automatically. In order to again proceed, it is necessary for theengineer to operate the release switch 87. This release switch may be enclosed in a lock box, the key of which is held by some other person, such as the conductor, 'for instance, or the release switch may only be accessible from the ground so that it is necessary for the engineer to wait at least until the trainis brought to a stop before the release switch 87 may be operated.

The circuit for picking up the electro-ie sponsive device of the train control device K may be traced as follows:-.-beginning at the terminal B of. the battery, contact 72, movable contact 7 6, wire 77, release switch 87, wires 91 and 80 winding 27 of the train control device K, w re 81, contacts 51, 50 and 52, wire 82, primary coil P,-wire 83, primary coil P, wire 84:, back to the common return wire N. v

The train control device K having now again been energized through its energizing iis circuit heretofore traced, including its stickup contact 28, allows the train to proceed untrain to any particular speed by spacing the track elements a distance which the ,train may travel at the speed in question during the time set off by the time control device TO. The operation of the automatic brake control apparatus is, therefore, dependent upon the' average-speed of the vehicle between a pair of track elements. Since these track elements are located relatively close together, this average speed approximates the actual speed when going over a secondv track element of such a pair.

Under clear traiiic conditions, that is, when the block in advance is not occupied, the track relay of the block in advance is energized, thereby closing its front contact 13 and energizing the several repeater track tolays 8 in the block, thus causing the coils 7 of the several pairs of track elements to beclosed in circuits of low resistance.

'Assummg now that a railway vehicle equipped with the apparatus illustrated in flux'will take place through the secondary Fig. 2 is passing'over a track element, having its coil in such a circuit of low resistance. As the car element L passes over the track element only avery slight change of coil S of the'car element L. This is accounted for by the fact that a slight change of flux through the track element causes a relatively large current to be setup in its coil 7 this current being in a direction to opposethe flux producing it. Since only a slight change of flux takes place through the secondary coil S under these conditions, the control relay C will not be deenergized, and therefore the other car-carried devices will not be influenced in passing over a track element closed in a circuit of low resistance.

characteristic may be taken advantage of in variops ways to provide thedesired regulation of tram movement under danger conditrons, that -1s, 1n a caution block, there is illustrated in Fig. 1 an arrangement in which the location and spacing of the pairs fof track elements are selected with a viewof "enforcing. speed limits, corresponding to those that are ordinarily observed by an en'- gineer in braking his train in obedience to a caution signal indication. The scheme fol curves, and such curves are shown in Fig, 1.

It should be understood that these'curves are merelyillustrative, and 'Will'vary to some degree in practice.

Referring to the curves in' Fig. 1, the solid line curve 92,- conveniently termed the brake j application curve, indicates the speed at the various points in the block at which the train may be traveling and yet, if a brake application is initiated, willbe brought to a stop at approximately the end of the block. The dot and dash curve 93 indicates in ageneral way the speeds at the various points in the block which it is assumed will ordinarily be observed by an engineer in braking his train in obedience to a caution signal. This curve 93 is based upon the assumption that an engineer, when his train enters the block at the maximum or relatively high speed, will immediately apply the brakes and bring the speed of his train down to some moderate speed at which his train is under better control, such as, for example, twenty-five miles per-hour; and after this intermediate control speed has been reached, the engineer brake application to bring his train to a.

stop at the right point.

In order to enforce speed limits icorresponding to those observed by the engineer .in the. regular braking of his train, shown by [the dot and dash curve 93, the location and spacing of the pairs of track" elements Tv are selected accordingly, In

the representative arrangement shown in Fig. 1, the last pair of track elements T"- are located at the point indicated by the line '95 where the control speed limit of twenty-five miles per hour, indicated by the line 96., intersects the brake ap lication curve 92. This particular location is chosen so that, if the train-should continue at about the control speed, to which it waslimite'd at the-next precedin pair of track elements T,

the automatic brae'application occurring at the second track element of the pair T" would bring the train to asto by the time added that this particular location of track it reached the end of the bloc It may be elements shown and described does not take into consideration the fact that the train ma trackelements T wonl'd belocated further a back from the exit-end of theblock,'so thateven afteraccelerating --from the control speed to which the train is limited at the track elements T, it could not attain a speed greater than that at' which it could be stopped in time by a brake application automatically initiated at the second track eler the end of the block. The engineer, however, I

ment of the pair T".

The spacing of the air of track elements T is selected to en orce some minimum speed limit, such as fifteen miles per hour, which the train, if braked in the ordinary way,would not exceed at the point indicated by the line 95. It is noted here that, while the curves shown in Fig. 1 are drawn with reference to the exit end of the block, they may be drawn with reference to some point a short distance from the exit end of the block so as to introduce an additional available brakin tions in the raking power of different trains of the same class under the different conditions affecting their brakin power. 1

The intermediate pair 0 track elementsv T? is located at some suitable point for the purpose of enforcing the intermediate control speed, assumed to be twenty-five miles per-hour. As shown, this pair of track elements T is located at the point, indicated by the line 97, corresponding .to the point in the block where the train is first brought down to said control speed. The trackeleline 97 intersects the brake application curve' 92, and where this line 98 intersects the curve 93 of train performance, is approximately the point (indicated by line 99) at which the second track element of the pair T should be located, the specific location, however, being preferably slightly in advance of said point of intersection, so as to have a slight,

difference in the speed limit automatically enforced and that. at which the train would ordinarily be running. The track elements performance curve,93, and, taking the fig ures assumed for the illustration of 'Fig. 1,

i said train continuesinto the block at about sixt miles per-hour, the brakes are auto-.

' matlcally app lied at the second element of distance to take care of varia-' running at a higher speed than that for which these track elements are spaced. Such automatic brake. application, initiated at the int indicated by the line 99, will act to f ing the train to a stop approximately at the track element location and spacing to be based upon acceleration, the automatic brake application occurring at the second track element of the pair T, will in a similar way bring the train to a stop in-time. If the engineer, however, is governing the train properl the speed will conform with that indicate by the curve 93, and the track elements T will be passed without such automatic brake application. In a similar way, the brakes will be automatically applied'by the pair of track elements T if the speed is excessive, but will not be applied if the train is being governed properly.

In the foregoing discussion of the curves of Fig. .1, it has been assumed that the train will not enter the block at a speed in excess ofsome normal or maximum speed for which the length of the block is fitted. Trains of different classes and schedules, however, do

not maintain the same maximum or normal running speed," and furthermore, the-same class or train may at times, iflbehind itsschedule, for example, run at an abnormally In order 4 high speed under clear signals. to avoid interference with train movements and permit attainment of full capacity, it is considered preferable, under 'most circumstances, to allow the trains to run at any maximum-or normal running speed under clear signals, and not impose any particular maximum or normal running speed limit. In. the interests of safety, since the block braking distance for excessive normal running speeds, one or more pairs of track elements or inductors, suita ly spaced apart, may be located back or in the rear of the entrance to each. block, or certain selected lengths may not always afford adequate no it blocks, these additional pairs acting to compel or enforce a reduction in speed from the highest attainable speed to a maximum conforming to that for which the length of the block and the pairs of track elements there'- in are selected. Thus, regardless of speed at which the train may be running, the engi- [neer is required to reduce that'speed upon the approach to a caution block, under penalty 0 an automatic brake application if he fails to'doso, with the result that the speed of the train entering the block will th pair T, since the train is assumed. t be be 9W e g so as t allowit to be stopped want the limits of the block, s also bring it within. the speed limits automatically en- I block. 1

i For illustrative purposes, one additional forced by the pairs'of track elements inthat 1, may be extended back into the block nextin the rear, as. far as desired, to follow out a curve starting at 7 5, 80- or even 90 miles per hour, corres onding. to the highest maximum or norxna running speed expected to exist, or which the trains may attain.

One important characteristicof the'speed control system embodying this invention is that any speed restrictions imposed in a caution block are instantly and automatically removed as soon as the block ahead clears, thereby permitting the train to-accelerate, if

' desired, without any interference by the automatic speed control system. Thus, if the engineer sees the signal at the entrance 'to' the next block in advance change from the stop position to either-the caution or clear position, he may, even'though about to pass over a pair of the track elements, as T, re-

lease the brakes, continue at speed',-or ac-' celerate, just as he desires. Such automatlc' removal of speed restrictions follows. from the fact that, as soon'as the track relay of the block ahead picks up, the coils 7 of all of the track elements of the block in the rear are placed on closed circuit, and do not produce any effect upon thecar apparatus of a passing'car, irrespective of the speed of that car. While the engineer under ordinary working conditions may be advised of a,

change in trafiic conditions in the next block in advance by reason of his ability to observe the signal at the entrance to said block in advance from a distance, if desired, re-' .p'eating signals, such as, changeable marker lights or color light signals, or the like,

shown conventionally and designated 102, may be located at several-points-throughout the block, preferably adjacent to the line relays 8, so that the engineer may more quickly. learn of a change in traflic conditions ahead.

It should be noted that the particular speed limit to be enforced or established at any given control point along the track is dependent upon the spacing of a pair of track elements at that point, and'by merely shortening or lengthening this spacing, the speed limit may be modified to any desired extent. Consequently, without undue complication or expense, any desired range or value of limited speeds may belaid down or prescribed for various points in different blocks along the railroad, takmg into account those conditions which cause variation.

ing should occur. For example, variations in the length of the blocks are taken care of-by locating the pairs of track elements in the speed limits at which automatic brakaccordingly. Variations in the safe and proper speed limits, due to changes in grade, eitherup or down grade, may likewise be compensated for by selecting thev location and spacing-of the pairs of track elements accordingly. In short, all parts of the-railroad may beengineered on their respective merits, so to speak, and the appropriate speed limits at any desired point inthe. several blocks may be provided, all by merely varying the' distance apart of the two track' elements of each pair.

Trains of different classes, for reasons well-known in the art, have different braking powers: and in accordance with this invention, it is contemplated that the timing device or contact TC will be designed or adjusted for the different trains to correspond with the braking power. Such adjustment or modification of the timing devipe varies with the speed limit at which an automatic brake application is produced by a given pair of track elementsspaced a certain distance apart. To illustrate, assuming, a pair of track elemeutsspaced88 feet apart, 1f the timing device is designed or adjusted for a one-second interval, the brakes will be 1 applied at speeds above 60 miles per hour,

if a two-second interval, at speeds abovefith,

miles per hour, and so on. V In addition to regulatingtlie "speed of trains in blocks to conform with danger conditions ahead, it is frequently desirable in practical operation to compel a train to observe some intermediate or slow speed irrespective of the presence or absence of other trains, inpassing through a certain zone or past a certain point, for example, the yard limits, bridges, down grades, approach to curves, crossovers or crossings constituting what may be conveniently termed perrna nent hazards, which 5 are points or regions where low speeds should be observed, re gardless of the presence of other trains ahead. Enforcement of the proper control for such fixed hazards is easily provided in accordance with this invention by locating one, or any number, of pails of track elements at the appropriate point, and spacing the elements of the pairs to accord'with the. limiting speeds desired, said track elements being permanently in the active stopping condition. For examplmthe 'trackway in block J is illustrated as having a short curve therein. and in order to restrict the speedof. the train at the approach to this curve, regardless of whether the block J or the block in advance thereof. is occupied or the normal direction of trafiic not, one or more pairs of track elements TP are located at points in the rear of said curve, three pairs of such track elements TP having been illustrated. These track elements TP, being intended to be always in the active stopping condition, are merely magnetic cores or-yokes without coils, and are con'iparatively cheap and easily installed. it should be understood that any number of these permanently acting pairs of track elements" may be located in the rear of the permanent hazard, and located in conformity with a brake application curve and train performance curve, similar to that shown and described with a caution block, or one pair of track elements, atthe appropriate point in the rear of the permanent hazard, may be employed to check-up the speed of 'the train and assure that its speed will not be excessive by the time .the permanent hazard is reached. Similarly, where it is desired to maintain throughout a zone or region of considerable extent, such as through yard limits or the -ike', several pairs of track elements, spaced the same distance apart, may be located at intervals to make sure that the tr'ain does not exceed such. low speed. It should be noted, however, that adjacent pairs of track elements can not be spaced so close together, that the second element of the first'pair and the first element of the second pair are not far enough apart to allow the desired speed. y In the foregoing description,-it has been assumed that the car is headed in the direction shown in Fig. 2, and is traveling in the railroad is signalled. In practical operation, however, it is sometimes necessaryfor the car to change end for end, and, travel in the same normal -direction of traflic. As previously stated, the, track elements are always located on one side of the track with respect to thenormal direction of traltic, in this instance, shown as the righthand side. WVith the car headed as shown in Fig. 2. and traveling in the normal direction of traffic, from left to right as indicated by the arrow, the. automatic reversing switch is frictionally driven from the car axle to connect the secondary coil S of the righthand car element to the control relay C. If the car should change end for end, and still travel in the normal direction of traffic, it can be seen that the direction of rotation of the car axle would be reversed, and this would shift the contactor 60 to the extreme position-against the etc 62, connecting wire 66 leading to the contro relay C to wire 103', connected to the secondary coil '8 of the other track element, which would now be on the righthand side of the vehicle and in position to pass over the track elements.

The contactor 60 is preferably constructed so as to change the connections between the some lowspeed f or which secondary coils of the two car elements without interrupting the circuit, that is, said contactor has make-before-break contacts.

Occasionally locomotives or whole trains run over the track opposite to the normal direction of traffic for which the railroad is signalled. It-is evident that thetrain in this instance would automatically put to stop ing rules; but in order to avoid complications incident to a cut-out device for cutting the car apparatus out of condition, it is die- Isirable to make provision such that the car receives no control from the trackway when making such a back-.up'movement. This de sir-able feature is taken care of in the system embodying this invention by the automatic reversing switch.

Referring to Fig. 2, it can be seen that,if the car'shown, instead of traveling from left to right, as indicated by the arrow, should reveise its direction of movement and travel opposite to the normal direction of traffic, the change in the direction of rotation of the car axle would automatically shift the contactor 60, cutting out the secondary coil of v the car element on the side of the track .where the track elements are located, with the result that the car would travel over the track without interference of the speed control system. As soon as the car reverses its direction of rotation, or passes on to a portion of the track where the track elements are on the right-hand side with respect to the direction 1n which the car is traveling, the desired control is automatically rein} stated.

The same arrangement ofcar and track equipment hereinbefore described -may be applied to single track railroads, as well as to,double track railroads, and used to or.-

forceobedience to the signalindications intrack elements on opposite sides of the track,

operatively coupled to their respective signals, gives an organization adaptable for governing train movement in either direction over said stretch of single track.

In order to explain the nature of the invention, and-the functions and mode of operation of the meansconstituting this invention, there has been shown and described one typical embodiment thereof, which has been selected more with a view of facilitating explanation of the invention, than for the purpose of disclosing the specific structure and arrangement of parts and circuits preferably employed in practice; and it should be un-- derstood that various adaptations, modifications and additions may be'made to this particular disclosure without departing from the invention. For example, it is contemplated that the system may be used in conjunction with any suitable or well-known type of block signal system, either direct current or alternating current, that various formsandtypes of sources for the electrical energy involved in the car operation may be employed, and that various forms of mechanism forcontrolling the application of the brakes andithe supply of propelling-power may be used and governed in the same way as the train control device K, such brake control mechanism being of course designed to effect an automatic brake application that can not be .forestalled or prevented by the engineer, and in a manner conforming with recognized air brake practice.

Other deviations from the specific disclosure will be evident to those-skilled in the art, and I desire to have it understood that the specific structure shown and described is merely illustrative of the invention, and does not exhaust the various embodiments thereof. 7

1. An automatic train control system coinprising, trackway elements located at one side of the center line of the track'rails each constituting a mass of inert'inagnetic material when in their active influence transmit ting condition, 'a car-carrie-d'core of magnetic materiahlmeans for producing a magneto-motive-torcein said core, a secondary coil on said core, a normally energized brake control appliance, and means for deenergiz ing said brake control appliance if said carcarried core passes over two successive trackway elements in less than a predetermined time.

2. In a'train control system, thecombination-of a railway track having a plurality ofpairs of inductive influence transmittingtrack elements associated therewith, each pair being spaced to enforce different predetermined speed limits, and car-carried apparatus comprising, inductive influence re ceiving means'including a normally energize'd stick relay, a normally energized-brake .control device maintained energized by a circuit including a front oontactof said device ltself, a time element device, means for de-energizing said brake; control device if said stick relay is de -energized twice in less than a predetermined period of time measured by said time element device, and manually operable means accessible only from the ground for closing a pick-up circuit for said spaced to enforce predetermined spee limits, and car-carried apparatus comprising, inductive influence receiving means including a relay, a normally energized brake control device energized by a circuit including afront contact of said device, a time element device controlled by said relay, two circuits for maintaining said brake control device inactive each including the front contact of said device, one of said circuits being opened momentarily when said relay is in its retracted position 1n response to the reception of a 'control influence and the other of said circuits being opened for a period of time measured by said time element device, and reset means which when in its active position bridges the front contact of said irake control device and opens the other of said two circuits.

4. In a train control system, the combinationof a brake control apparatus on'a'velncle, a plurality of pairs of track elements,

located outside the track rails, a car element on the vehicle adapted to be influenced by said track elementsfthrou h an intervening air gap when said track e ements are in their influence transmitting condition, and means for actuating said brake control apparatus when thevehicle traverses the spacebetween a pair of said track elements in less than a predetermined time. V i

'5. In a train control system, the combination of a brake control apparatus on :1 vehicle, a plurality of pairs of track devices, car-carried influence receiving means on opposite sides of the vehicle; means to operatively couple the influence receiving means.

on a particular side of the vehicle. (with respect to the direction of the movement of the vehicle) to said brake control apparatus;

and means to actuate said brake-control apparatusif the vehicle traversesthe space between a pair oftrack devices in less than a predetermined time.

6., Ina tram control system, thecom'oination of a railway track 'div1dedintoblocks,

lot

each block having a plurality of pairs of inductive influence transmitting track elements associated therewith each air being spaced to enforce different pre etermined speed limits, and car-carried apparatus comprising, an inductive influence receiving means including a stick relay de-energized upon the reception of .a control influence from said track elements, a brake control device, a time element device set into operation upon deenergization of said relay, two circuits for maintaining said brake control device energized and inactive, one of said circuits being controlled by said relay and opened momentarily during the dropping and picking up of said stick relay, and the other of said circuits being opened for a predetermined time by said time element device following the reception of a control'influence,,and a pick-up circuit for said relay closed only if said time element device has attained its normal condition arid said relay is deenergized.

7. Car-carried apparatus for train control systems comprising, influence receiving means, a brake control apparatus, and means for actuating said brake control apparatus when two successive influences are received in less than a predetermined time, said means including a time element device adapted to be driven by a continuously rotating shaft, and means for applying the brakes if said shaft rotates at less than a predetermined speed. Y 8. car carried apparatus for train control systems comprising, a control-relay connected in a stick circuit, means actuated from the trackway'for governing said control relay, a time controlled device for interrupting a circuit for a predetermined time by opening contacts for such a time and means for picking up said controlrelay operative onl when said last mentioned contacts are close 9. Car-carried apparatus for train control systems, the combination of brake control apparatus actuated when two successive in-i fluences are received in less than a predetermined time measured by. a time controlled device, said time controlled device comprising, a motor operated at a substantially constant speed, a movable element driven by said motor through the medium of a friction clutch, and means for at times preventing the movement ofsaid element.

10. In an automatic train control system ,for railroads having tracks divided into blocks, the combination of a plurality of pairs of track elements in each block, each track clement constituting an inert magnetic body when in its active stopping condition, a line relay associated with each pair of track elements and overning the controlling condition thereof, receiving means on a 'vehicle influenced by said track elements,

and brake controlling means on the vehicle each pair having a coil thereon closed in' a deenergized circuit of low resistance in the absence of trains in the block next in advance.

12.- Car carried apparatus for automatic train control systems comprising, influence receiving means, a brake setting appliance',. means including a time element device set into operation by the reception of an impulse by said impulse receiving meansfor, actuating said brake setting appliance Whenever two successive influences are received in less than, a predetermined interval of time, said brake setting appliance whenever actuated remaining in that condition until restored, and manually operable means for restoring said brake setting appliance, said\ manually operable means when in its active condition causing said brake setting appliance to be thereafter actuated upon the reception of a single control influence.

13. In an automatic train controlap'para- I tllS-z-fOI railway vehicles, timing mechanism comprising, a constantly rotating shaft driven at a substantially constant speed,-

-contacts opened during a predetermined-extent of rotation of said shaft, and speed rearresting said rotary element, brake control apparatus governed by said rotary element, 1

and a centrifugal device connected to said shaft and acting automatically to actuate said brake control apparatus whenever the speed ofsaid shaft falls below a predetermined value. 1

15. In a system for producing automatic brake applications on railway vehicles dependent on their speed as determined by the time consumed in running a'predetermined I, distance, pairs of track elements disposed at intervals along the track on one side of the center line thereof, car-carried elements onopposite sides of the center line of avehicle adapted to cooperate withflthe track elements through an intervening air gap, and-means dependent on the direction of movement of the vehicle and which end is leading for rendering effective that car elementon the side of the car Where the said pairs of track elements are located so long as the car travels in the normal direction of traffic. I

16. In an automatic train control system for governing the speed of a railway vehicle in accordance with the time-distance, interval principlein the manner described, a railroad track divided into blocks, a-plurality of pairs of inductive track elements associated with each block, the track elements of each pair being spaced a different distance apart, a coil associated with at least one of spaced a predetermined distance apartalong the trackway,said trackwayelements comprising mert non-magnetized magnetic bodms, at car-carried core of magnetic material located on one side of the center line of the vehicle to cooperate with said trackway elements in the movement of the vehicle, means for producing a magneto-motive force in said core, a secondary coil onsaid core, a train brake control device and means for initiating said control device to apply the vehicle brakes if the vehicle is traveling at more than a predetermined speed while said car-carried core passes over said two traclc way elements.

18. Car equipment for train control systems comprising, a brake control device, a normally energized stick relay, means influenced fronrthe track a for breaking the stick circuit of said re ay, a normally energized repeater relay governed by said stick relay for closing apick-up circuit for said stick relay when deenergized, and time controlled means initiated when said repeater relay is actuated for actuating said brake control device if two successive influences are received from the trackway in less than a predetermined interval of time.

19. An automatic train control system comprising,a car element having a secondary coil thereon, a time element device, a norn'ially energized control relay for initiating said time element device when deenergized, a brake control appliance governed jointly. by said control relay and-said time element device and actuated if said. relay deenergized two times in less than a predetermined time measured by said device said brake control appliance when actuated remaining actuated'until speciallyrestored, and trackwa devices each including a core having a coi thereon for deenergizmg said control relay when saidv car element passes over said track element and said coil is open-circuited and not deenergizing said relay when said coil is closed in a circuit oi low resistance.

20. Gar-carried apparatus for automatic train control systems comprising, a normally energized control relay connected in astick circuit, a normally energized repeater relay governed by said control relay, means for picking up said control relay by said repeater relay upon deenergization of said repeater relay, :1. time element-device initiated upon deenergization of said repeater relay, a normally energized brake control appliance, and means. controlled jointly by said repeater relay and said time element device for deenergizing said brake control appliance if said repeater relay is deenergized two times in less than a predetermined time.

21. Automatic car-carried means for aptravels between two successive. points in less than a predetermined time comprising, time controlled means having a'cycle of operation and including a rotary shaft, and means detecting cessation of rotation of said shaft.

plying the brakes thereof when the car a 22. Brake control apparatus for train control systems of the character described comprising, anormally energized main con: trol relay connected in a stick circuit, an electro responsive repeater relay controlled by said control relay, timecontrol mechanism and a brake-settingappliance, said devices enumerated cooperating to produce an automatic brake application if two successive operationsof the control relay occur in less than a predetermined time.

23. Car-carried apparatus for automatic train control systems comprising, a normally'energized electro-pnenmatic brake COD. trol appliance connected in a stick circuit including a front contact of said device, two contacts in multiple for controlling said cir cuit, a' relay controlled by influences trans mitted from the trac'kw'ay for operating one of said contacts, a time'element devic'e controlled by said relay for operating the other contact, whereby operation of both of said contacts simultaneously deenergizes said brake control appliance, and a pick-up'cii cuit for said brake control applianceincluding a push button only accessible from the ground for again picking up said brake control appliance.

24. A system for compelling a yehicle to maintain successivel lower speeds in traveling through a bloc in order to avoid an automatic brake application comprising, a plurality of pairs of closely spaced magnetic bodies located at intervals along the trackway and outside of the track rails, one magnetic body of each pair having a coil thereon closed in a circuit of low resistance under clear. traflic conditions ahead.

25. A system of speed-control of the character described comprising, pairs 'of track elements requiring no electrical energy a normally energized contro to assume either the active or inactive condition, together with car elements on op posite sides of the car adapted to cooperatewith said trackelements and automatically rendered alternately effective dependent upon the direction of movement of the car and which end is leading, and brake control mechanism including time control means for producing an automatic brake application whenever two successive influences are communicated from the tra'ckway in less than a predetermined interval of time.

' 26. A train control system'comprising, a car-carried yoke of magnetic material having a primary and a secondary"coil thereon, a normally energized brake control 'device connected in series with said primary-coil,

nected in series with said secondary coil,

and means controlled by said control relay for deenergizing said brake control device if twocontrol influences are received by said secondary coil in less than a predetermined interval of time.

27. Car-carried apparatus for automatic train control systems comprising, 'a normally energized brake control appliance actingon the usual air brake system which'applies the brakes of the vehicle when deenergized, influence receiving means located equal distances on-opposite sides. of the center line on the vehicle and adapted to receive control influences from suitable cooperating trackway devices located along the trackway, an electro-responsive control device, means automatically operated in accordance with'the direction of movement of the vehi- I cle for operativel connecting said control device to one or t ie otherof said influence receiving means, and means for decnergizing said brake control appliance if two successive control influences are transmitted to said control device in less than a prede-. tei'mined interval of time.-

28. Car-carried apparatus for automatic train controlsystemscomprising, a normally energized brakev control appliance adapted to apply the brakes of the vehicle when 'deenergized, two similar circuits on the vehicle each. of which is adapted to be influenced -from the trackway, an electromesponsive device, means automatically oper-.

ated in accordance with the direction of 'movement of the vehicle for operatively relay conenergizing said brake control appliance if said control device is deenergize'd two times in less than a predetermined time, manually operable means accessible only from the ground for restoring saidbrake control appliance, and means forapplying the brakes regardlessof speed if said manually operable means is maintained in the restoring position.

30. Car-carried apparatus for. automatic. train control systemscomprising, a normally energized electro-responsive control device momentaril deenergized upon the reception of a control influence fromthe trackway, a

time element device initiated upon deenergization of said control device, normally ener'gizedbrake control appliance acting to apply the usual air brakes of the vehicle when deenergized which if momentarily deenergized will remain in the deenergized position until restored, and which is deenergized if two control influences are received by said control device in less than apredetermined time measured by said 100' time element device, and manually operable meansfor restoring said brake control appliance only operable if-the vehicle has been brought to a stop.

31. Ina train control system, the-combination with car-carried equipment for train control systems compris ng, an impulse receiving device on each side of the car, a

normally energized control relay, a brake. control -appliance, means including a time 1 element device for deene'rgizing said brake control appliance if two successive impulses are received by said control relay in less than "a predetermined time, and automatic means dependent for its peration upon the re- 115 "versalof the direction of rotation of the car wheels for alternately operatively connecting said impulse receiving devices to said control relay.

In testimony whereof 'I hereby aflii: my 125 signature. I i

WINTHROP K. owe. 

